entCatAD allows you to test and improve your knowledge of history. There are five categories that you can choose from: Politics & History, Arts & Literature, Daily Life, Science & Technology, and Religion & Philosophy. After selecting a category, select a century (1st through 20th). In most categories, the nearer centuries (e.g., 20th, 19th, etc.) have more questions than the earliest centuries (1st, 2nd, 3rd, etc.). You can subsequently save your score, and then view a report of scores by category, by century, or an overall listing of scores. Multiple players can store their scores separately. The History & Politics and Daily Life categories are free and enabled right away. To access the other three categories, you must first pay for the product (which you can do online via a menu item).